Wheel Assembly

ABSTRACT

A wheel assembly for a vehicle includes a knuckle having an upper end and a lower end. A bracket is mounted to one of the upper end and the lower end of the knuckle by a plurality of fasteners. A ball joint is mounted to the bracket and configured for attaching the wheel assembly to the vehicle. One of the knuckle and the bracket defines a boss and the other defines a bore. The boss is slideably disposed within the bore in slip fit engagement. The boss transfers a load between the knuckle and the bracket in both a vertical direction along a king pin axis and a horizontal direction along a longitudinal axis of the vehicle.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Non-Provisional PatentApplication Ser. No. 12/967,575 filed Dec. 14, 2010, now U.S. Pat. No.______, which is a continuation of U.S. Non-Provisional PatentApplication Ser. No. 12/239,174 filed Sep. 26, 2008, now U.S. Pat. No.7,850,179, which claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/977,959 filed Oct. 5, 2007, the disclosures ofwhich are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention generally relates to a wheel assembly for avehicle.

2. Description of the Prior Art

Wheel assemblies generally include a knuckle. A wheel hub is rotatablysupported by the knuckle. The knuckle is coupled to the vehicle by anupper ball joint and a lower ball joint. The upper ball joint and thelower ball joint are concentric with and aligned along a king pin axis.The upper ball joint and the lower ball joint may be mounted to an upperbracket and a lower bracket respectively, with the upper bracket and thelower bracket mounted to the knuckle by a plurality of fasteners, suchas by bolts. Accordingly, the fasteners provide a clamping force tomount the brackets to the knuckle. Additionally, the fasteners transfera load, i.e., a force, between the knuckle and the upper bracket and thelower bracket. This load is considerable when the wheel assembly isutilized in heavy duty vehicles, such as in commercial off-road use andin military applications.

The knuckle, the upper bracket and the lower bracket are typicallymanufactured from steel in order to adequately transfer the load betweenthe knuckle and the upper and lower brackets to the fasteners connectingthe upper and lower brackets to the knuckle. Having the knuckle, theupper bracket and the lower bracket manufactured from steel increasesthe weight of the wheel assembly, which increases the overall weight ofthe vehicle and thereby negatively affects fuel efficiency of thevehicle.

SUMMARY OF THE INVENTION AND ADVANTAGES

The subject invention provides a wheel assembly for a vehicle. The wheelassembly comprises a knuckle. The knuckle includes an upper end and alower end spaced from the upper end along a king pin axis. A bracket ismounted to one of the upper end and the lower end of the knuckle. Thebracket defines a king pin aperture concentric with the king pin axis.The king pin aperture receives a ball stud within the king pin aperture.One of the knuckle and the bracket defines a boss and another of theknuckle and the bracket defines a bore. The boss is in slip fitengagement within the bore. The boss transfers a load between theknuckle and the bracket vertically along the king pin axis andhorizontally along a longitudinal axis of the vehicle. The longitudinalaxis of the vehicle is generally transverse to the king pin axis.

Accordingly, the wheel assembly of the subject invention utilizes theboss to transfer the load, i.e., a force between the knuckle and thebracket. The use of the boss to transfer the load between the knuckleand the bracket permits the knuckle to be manufactured from alightweight material, such as aluminum, thereby reducing the weight ofthe wheel assembly. Furthermore, the boss reduces the load transferredbetween the knuckle and the bracket by a plurality of fastenersinterconnecting the knuckle and the bracket, which improves a clampingforce applied by the fasteners to the knuckle and the bracket.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated,as the same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a perspective view of a wheel assembly;

FIG. 2 is a cross sectional view of the wheel assembly;

FIG. 3 is a rear plan view of the wheel assembly;

FIG. 4 is a perspective view of a bracket of the wheel assembly;

FIG. 5 is a cross sectional view of the bracket along cut line 5-5 shownin FIG. 4;

FIG. 6 is a top plan view of the bracket; and

FIG. 7 is a front plan view of the bracket.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the Figures, wherein like numerals indicate correspondingparts throughout the several views, a wheel assembly is shown generallyat 20. The wheel assembly 20 is for a vehicle and rotatably supports awheel hub 22. A wheel (not shown) is mounted to the wheel hub 22, and atire (not shown) is mounted to the wheel as is well known. It should beappreciated that the wheel hub 22 may include any suitable hub assembly,and specifically may include an electric drive hub assembly, a gearreduction hub assembly, or some other hub assembly particularly suitedfor heavy duty vehicles and/or off-highway applications. It should alsobe appreciated that the scope of the claims are not limited by the typeand configuration of the wheel hub 22.

Referring to FIGS. 1 through 2, the wheel assembly 20 includes a knuckle24. The wheel hub 22 is rotatably mounted to the knuckle 24. The knuckle24 includes an upper end 26 and a lower end 28. The lower end 28 of theknuckle 24 is vertically spaced from the upper end 26 of the knuckle 24along a king pin axis 30.

A bracket 32 is mounted to one of the upper end 26 and the lower end 28of the knuckle 24. Preferably, the bracket 32 includes an upper bracket32A mounted to the upper end 26 of the knuckle 24 and a lower bracket32B mounted to the lower end 28 of the knuckle 24. It should beappreciated that throughout the detailed description of the subjectinvention, reference to “the bracket 32” describes both the upperbracket 32A and the lower bracket 32B unless otherwise noted. However,within the scope of the claims, the recited term “the bracket 32” refersto either the upper bracket 32A or the lower bracket 32B and should notbe limited to require both the upper bracket 32A and the lower bracket32B unless specifically recited.

Referring Also to FIGS. 4 through 7, the bracket 32 defines a pluralityof fastener apertures 34. The fastener apertures 34 extend transverse tothe king pin axis 30 and are generally perpendicular to the knuckle 24.The wheel assembly 20 further includes a plurality of fasteners 36. Eachof the plurality of fasteners 36 is slideably disposed within one of theplurality of fastener apertures 34. Each of the fasteners 36 is inthreaded engagement with one of the knuckle 24 and the bracket 32. Asshown, the fasteners 36 are in threaded engagement with the knuckle 24.The fasteners 36 provide a clamping force to bias the knuckle 24 and thebracket 32 together.

The bracket 32 includes a body 38. The body 38 of the bracket 32 definesa king pin aperture 40. As best shown in FIG. 2, the king pin aperture40 receives a ball stud 42 of a ball joint therein. The ball jointcouples the wheel assembly 20 to the vehicle as is well known in theart. Preferably, and as shown, the wheel assembly 20 includes an upperball stud 42A mounted to the upper bracket 32A and a lower ball stud 42Bmounted to the lower bracket 32B.

One of the knuckle 24 and the bracket 32 defines a boss 44. Another ofthe knuckle 24 and the bracket 32 defines a bore 46. Preferably, and asbest shown in FIG. 2, the bracket 32 includes the boss 44 and theknuckle 24 defines the bore 46. As shown, the boss 44 extends from thebody 38 of the bracket 32 along a central axis 48. Preferably, the body38 and the boss 44 are integrally formed. However, it should beappreciated that the boss 44 may be a separate piece from both theknuckle 24 and the bracket 32 and fixedly mounted to one of the knuckle24 and the bracket 32.

The boss 44 is disposed within the bore 46 in slip fit engagement withinthe bore 46. Accordingly, the bore 46 includes a cross section defininga shape. The boss 44 also includes a cross section defining a shapecomplimentary to the cross sectional shape of the bore 46. The crosssectional shape of the boss 44 mates with the cross sectional shape ofthe bore 46 in a tight lash free engagement so as to permit loadtransfer therebetween in all directions radially about the central axis48.

Preferably, and as shown, the cross sectional shape of the bore 46 andthe cross sectional shape of the boss 44 include a circular crosssectional shape. The boss 44 includes a boss diameter 50 and the bore 46includes a bore diameter 52. The bore diameter 52 is between the rangeof 40 microns and 120 microns larger than the boss diameter 50.Preferably, the diameter of the boss 44 is at least 20 mm. Even morepreferably, the diameter of the boss 44 is at least 25 mm. While theboss 44 and the bore 46 are both shown as having a circular crosssectional shape, it should be appreciated that the cross sectional shapeof the boss 44 and the cross sectional shape of the bore 46 may includeshapes other than circular, such as a square cross sectional shape, ahexagonal cross sectional shape, etc.

The boss 44 extends from the knuckle 24 or the body 38 of the bracket 32a boss length 54. The bore 46 extends into the knuckle 24 or the body 38of the bracket 32 a bore distance 56. The bore distance 56 is greaterthan the boss length 54. Accordingly, an end of the boss 44 does notcontact an end of the bore 46 so that any debris caught within the bore46 does not interfere with the boss 44. As shown, the knuckle 24 definesthe bore 46 and the bore distance 56 and the bracket 32 includes theboss 44, which defines the boss length 54. Preferably, the boss length54 is at least 15 mm. Even more preferably, the boss length 54 is atleast 19 mm.

As described above, the boss 44 extends from the body 38 along thecentral axis 48. The central axis 48 intersects the king pin axis 30with the boss 44 concentric with the central axis 48. Preferably, thecentral axis 48 intersects the king pin axis 30 at a non-perpendicularangle 58 relative to the body 38 as shown in FIG. 5. The angledintersection between the central axis 48 and the king pin axis 30 allowsthe central axis 48, and therewith the boss 44, to extend in a generallyhorizontal direction with the king pin axis 30 angled away from verticalto provide a proper ride alignment for the vehicle as is well known inthe art.

Preferably, the knuckle 24 is manufactured from aluminum to reduce theweight of the wheel assembly 20, with the bracket 32 being manufacturedfrom steel to provide sufficient strength. However, it should beappreciated that the knuckle 24 may be manufactured from a materialother than aluminum, such as steel; and the bracket 32 may bemanufactured from a material other than steel, such as cast iron.

The boss 44 transfers a load between the knuckle 24 and the bracket 32vertically along the king pin axis 30 and horizontally along alongitudinal axis 60 of the vehicle. The longitudinal axis 60 isgenerally transverse to the king pin axis 30 and extends between a frontof the vehicle and a rear of the vehicle.

The vehicle includes multiple wheel assemblies 20, which transfer theweight of the vehicle, i.e., the load, to a surface, and likewisetransfer a reactionary load from the surface to the vehicle. The tightlash-free fit between the boss 44 and the bore 46 transfer the loadbetween the knuckle 24 and the bracket 32. Because the boss 44 and thebore 46 include the complimentary cross sectional shapes, the boss 44 iscapable of transferring the load between the knuckle 24 and the bracket32 in any direction extending radially outward from the central axis 48.

It should be appreciated that the magnitude of the load that may betransferred is dependent upon the shear strength of the boss 44. Theshear strength of the boss 44 is dependent upon, among other factors, amaterial strength of the boss 44 and the cross sectional area of theboss 44 perpendicular to the central axis 48. By increasing the crosssectional area of the boss 44, the shear strength of the boss 44increases. The boss 44 therefore increases the shear strength betweenthe knuckle 24 and the bracket 32 beyond that provided by the fasteners36 connecting the bracket 32 to the knuckle 24. Accordingly, if sodesired, the boss 44 may be designed to transfer the entire load and thefasteners 36 may be sized to merely provide the necessary clampingforce. Additionally, the boss 44 may be sized to permit use of differentmaterials having different material strengths.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology which has been used is intended to bein the nature of words of description rather than of limitation. As isnow apparent to those skilled in the art, many modifications andvariations of the present invention are possible in light of the aboveteachings. The use of the word “said” in the apparatus claims refers toan antecedent that is a positive recitation meant to be included in thecoverage of the claims whereas the word “the” precedes a word not meantto be included in the coverage of the claims. In addition, the referencenumerals in the claims are merely for convenience and are not to be readin any way as limiting. It is, therefore, to be understood that withinthe scope of the appended claims, the invention may be practicedotherwise than as specifically described.

1. A wheel assembly for a vehicle, said assembly comprising: a knucklehaving an upper end and a lower end spaced from said upper end; abracket mounted to one of said upper end and said lower end of saidknuckle and defining an aperture for receiving a ball stud within saidaperture; and one of said knuckle and said bracket defining a boss andanother of said knuckle and said bracket defining a bore with said bossin slip fit engagement within said bore to transfer a load between saidknuckle and said bracket both vertically and horizontally with respectto a longitudinal axis of the vehicle.
 2. An assembly as set forth inclaim 1 wherein said bore includes a cross section defining a shape andwherein said boss includes a cross section defining a shapecomplimentary to said cross sectional shape of said bore for mating withsaid cross sectional shape of said bore.
 3. An assembly as set forth inclaim 2 wherein said cross sectional shape of said bore and said crosssectional shape of said boss include a circular cross sectional shape.4. An assembly as set forth in claim 1 wherein said boss includes adiameter and said bore includes a diameter between the range of 40microns and 120 microns larger than said diameter of said boss.
 5. Anassembly as set forth in claim 4 wherein said diameter of said boss isat least 20 mm.
 6. An assembly as set forth in claim 5 wherein saiddiameter of said boss is at least 25 mm.
 7. An assembly as set forth inclaim 1 wherein said bracket includes a body with said boss extendingfrom said body along a central axis.
 8. (canceled)
 9. (canceled)
 10. Anassembly as set forth in claim 7 wherein said body and said boss areintegrally formed.
 11. An assembly as set forth in claim 7 wherein saidknuckle defines said bore.
 12. An assembly as set forth in claim 7wherein said boss extends from said body of said bracket a boss lengthand said bore extends into said knuckle a bore distance with said boredistance greater than said boss length.
 13. An assembly as set forth inclaim 12 wherein said boss length is at least 15 mm.
 14. An assembly asset forth in claim 13 wherein said boss length is at least 19 mm.
 15. Anassembly as set forth in claim 1 wherein said bracket defines aplurality of fastener apertures extending generally perpendicular tosaid knuckle.
 16. An assembly as set forth in claim 15 furthercomprising a plurality of fasteners with each of said plurality offasteners slideably disposed within one of said plurality of fastenerapertures and in threaded engagement with said knuckle.
 17. An assemblyas set forth in claim 1 wherein said knuckle is manufactured fromaluminum.
 18. An assembly as set forth in claim 1 wherein said bracketincludes an upper bracket mounted to said upper end of said knuckle anda lower bracket mounted to said lower end of said knuckle.
 19. Anassembly as set forth in claim 1 further comprising a wheel hubrotatably mounted to said knuckle.